RandomStr.java

package FlexibleEncoding.Parquet;

import java.util.Random;

public class RandomStr {
	  private final char[] alphanumeric=alphanumeric();
	  private final Random rand;

	  public RandomStr(){this(null);}

	  public RandomStr(Random rand){
	    this.rand=(rand!=null) ? rand : new Random();
	  }

	  public String get(int len){
	    StringBuffer out=new StringBuffer();

	    while(out.length() < len){
	      int idx=Math.abs(( rand.nextInt() % alphanumeric.length ));
	      out.append(alphanumeric[idx]);
	    }
	    return out.toString();
	  }

	  // create alphanumeric char array
	  private char[] alphanumeric(){
	    StringBuffer buf=new StringBuffer(128);
	    for(int i=48; i<= 57;i++)buf.append((char)i); // 0-9
	    for(int i=65; i<= 90;i++)buf.append((char)i); // A-Z
	    for(int i=97; i<=122;i++)buf.append((char)i); // a-z
	    return buf.toString().toCharArray();
	  }
	}